This invention relates generally to the art of computer graphics, and more specifically to the field of point sampling of visual scene information for the purpose of reconstructing an image of the visual scene.
One form of computer graphics that is becoming widely practiced is to develop the sequence of video image frames of a moving object scene from information of the scene that has been stored in a computer memory. The object scene database contains information of the visual characteristics of the object scene, such as color, as well as information of movement. The creator of a sequence of video frames then uses a computer to electronically assemble signals of each video frame from the database in a manner that provides the views and movement of the object scene that is desired by the operator to be displayed.
The electronic signal for each video frame is typically developed by electronic sampling of the object scene database. A separate set of digital signals is developed to represent the color and/or intensity of each pixel of a standard raster scanned video monitor, for each video frame produced. Each pixel is thus the smallest resolution element of the video display. The color and/or intensity of each pixel is determined by sampling the database information to determine the characteristics of the object scene at the location of a given pixel. Such sampling is generally done by averaging the object scene information over a certain portion of the area of the pixel, or, more commonly, to sample the information at one or more points within the pixel, usually in some form of a periodically repeating pattern.
Recent developments in the field of computer graphics have been directed to increasing the realism of the resulting images. Progress has been made in more faithfully reproducing object textures, shadows, reflections and transparencies, for example. Much effort has been directed to the problem of aliasing, as well. Existing sampling techniques tend to generate video image frames having "alias" images; that is, images that appear to be real but which are not specified in the computer database. This is generally recognized as a characteristic of images formed through variously used point sampling techniques.
Therefore, it is a general object of the present invention to provide computer graphics techniques that further improve the realism of the resulting video image frames and the totality of video productions generated from computer database representations of an object scene.